/*******************************************************************************
 * Copyright (c) 2013, Daniel Murphy
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * 	* Redistributions of source code must retain the above copyright notice,
 * 	  this list of conditions and the following disclaimer.
 * 	* Redistributions in binary form must reproduce the above copyright notice,
 * 	  this list of conditions and the following disclaimer in the documentation
 * 	  and/or other materials provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 ******************************************************************************/

package org.jbox2d.common;

import java.io.Serializable;

// updated to rev 100

/** A transform contains translation and rotation. It is used to represent the position and orientation of rigid frames. */
public class Transform implements Serializable {
	private static final long serialVersionUID = 1L;

	/** The translation caused by the transform */
	public final Vec2 p;

	/** A matrix representing a rotation */
	public final Rot q;

	/** The default constructor. */
	public Transform () {
		p = new Vec2();
		q = new Rot();
	}

	/** Initialize as a copy of another transform. */
	public Transform (final Transform xf) {
		p = xf.p.clone();
		q = xf.q.clone();
	}

	/** Initialize using a position vector and a rotation matrix. */
	public Transform (final Vec2 _position, final Rot _R) {
		p = _position.clone();
		q = _R.clone();
	}

	/** Set this to equal another transform. */
	public final Transform set (final Transform xf) {
		p.set(xf.p);
		q.set(xf.q);
		return this;
	}

	/** Set this based on the position and angle.
	 * 
	 * @param p
	 * @param angle */
	public final void set (Vec2 p, float angle) {
		this.p.set(p);
		q.set(angle);
	}

	/** Set this to the identity transform. */
	public final void setIdentity () {
		p.setZero();
		q.setIdentity();
	}

	public final static Vec2 mul (final Transform T, final Vec2 v) {
		return new Vec2((T.q.c * v.x - T.q.s * v.y) + T.p.x, (T.q.s * v.x + T.q.c * v.y) + T.p.y);
	}

	public final static void mulToOut (final Transform T, final Vec2 v, final Vec2 out) {
		final float tempy = (T.q.s * v.x + T.q.c * v.y) + T.p.y;
		out.x = (T.q.c * v.x - T.q.s * v.y) + T.p.x;
		out.y = tempy;
	}

	public final static void mulToOutUnsafe (final Transform T, final Vec2 v, final Vec2 out) {
		assert (v != out);
		out.x = (T.q.c * v.x - T.q.s * v.y) + T.p.x;
		out.y = (T.q.s * v.x + T.q.c * v.y) + T.p.y;
	}

	public final static Vec2 mulTrans (final Transform T, final Vec2 v) {
		final float px = v.x - T.p.x;
		final float py = v.y - T.p.y;
		return new Vec2((T.q.c * px + T.q.s * py), (-T.q.s * px + T.q.c * py));
	}

	public final static void mulTransToOut (final Transform T, final Vec2 v, final Vec2 out) {
		final float px = v.x - T.p.x;
		final float py = v.y - T.p.y;
		final float tempy = (-T.q.s * px + T.q.c * py);
		out.x = (T.q.c * px + T.q.s * py);
		out.y = tempy;
	}

	public final static void mulTransToOutUnsafe (final Transform T, final Vec2 v, final Vec2 out) {
		assert (v != out);
		final float px = v.x - T.p.x;
		final float py = v.y - T.p.y;
		out.x = (T.q.c * px + T.q.s * py);
		out.y = (-T.q.s * px + T.q.c * py);
	}

	public final static Transform mul (final Transform A, final Transform B) {
		Transform C = new Transform();
		Rot.mulUnsafe(A.q, B.q, C.q);
		Rot.mulToOutUnsafe(A.q, B.p, C.p);
		C.p.addLocal(A.p);
		return C;
	}

	public final static void mulToOut (final Transform A, final Transform B, final Transform out) {
		assert (out != A);
		Rot.mul(A.q, B.q, out.q);
		Rot.mulToOut(A.q, B.p, out.p);
		out.p.addLocal(A.p);
	}

	public final static void mulToOutUnsafe (final Transform A, final Transform B, final Transform out) {
		assert (out != B);
		assert (out != A);
		Rot.mulUnsafe(A.q, B.q, out.q);
		Rot.mulToOutUnsafe(A.q, B.p, out.p);
		out.p.addLocal(A.p);
	}

	private static Vec2 pool = new Vec2();

	public final static Transform mulTrans (final Transform A, final Transform B) {
		Transform C = new Transform();
		Rot.mulTransUnsafe(A.q, B.q, C.q);
		pool.set(B.p).subLocal(A.p);
		Rot.mulTransUnsafe(A.q, pool, C.p);
		return C;
	}

	public final static void mulTransToOut (final Transform A, final Transform B, final Transform out) {
		assert (out != A);
		Rot.mulTrans(A.q, B.q, out.q);
		pool.set(B.p).subLocal(A.p);
		Rot.mulTrans(A.q, pool, out.p);
	}

	public final static void mulTransToOutUnsafe (final Transform A, final Transform B, final Transform out) {
		assert (out != A);
		assert (out != B);
		Rot.mulTransUnsafe(A.q, B.q, out.q);
		pool.set(B.p).subLocal(A.p);
		Rot.mulTransUnsafe(A.q, pool, out.p);
	}

	@Override
	public final String toString () {
		String s = "XForm:\n";
		s += "Position: " + p + "\n";
		s += "R: \n" + q + "\n";
		return s;
	}
}
